The present invention relates to a method for controlling an engine for driving a hydraulic pump which generates pressurized fluid to drive a hydraulic actuator for a construction equipment and, more particularly, to a method for controlling an engine wherein the number of revolutions (rotational speed) of the engine is controlled in accordance with operating conditions of a hydraulic pump for a hydraulic actuator used in a construction equipment.
In a conventional method of controlling an engine for driving a hydraulic pump which generates hydraulic pressure to drive hydraulic actuators for construction equipment, as disclosed in the specification and the appended drawings of, for example, Japanese Patent Application No. 55-42840, when it is sensed that an operating lever by which an operator manipulates the hydraulic actuators occupies a position for stopping operations of all the hydraulic actuators over a certain period of time, the number of revolutions of the engine is reduced to less than the revolution number of the engine during normal operation. After the revolution number of the engine is thus reduced, when the operating lever is displaced from the position for stopping the operations of the hydraulic actuator, in order to drive at least one hydraulic actuators, the displacement of the operating lever is sensed so that the revolution number of the engine returns to the revolution number for the normal operation. In this conventional method, the control of the engine revolution number is performed only on the basis of the position of the operating lever handled by the operator.